Small-sized hoist device

ABSTRACT

In a small-sized hoist device, an inner annular member disposed in spaced relationship to an outer annular member is employed in transmitting the input force to the drive shaft. The inner annular member is mounted and rotates with the shaft while the input force is delivered to the outer annular member which conveys the force through interlocking means to the inner member. The interlocking means comprises a cage member holding a plurality of balls which fit into continuous threads formed in the oppositely arranged facing surfaces of the inner and outer annular members.

1,863,556 6/1932 Cottrell....,................... 188/829 Tokyo; 2,390,891 12/1945 Martin....... 254/186 HC TakeshiSaito,Kawasaki-shi, both ofJapan 2,783,861 3/1957 .lungles......... 192/8 [21] AppLNo. 800,662. 3,047,114 7/1962 Stevens, Jr.... 192/16 Feb. 19, 1969 3,399,867 9/1968 Schroeder.................... 254/168 [45] Patented net. 7, 1971 FOREIGN PATENTS Kabushiki Kaisha Klto Selsakusho xawmkhshi,Kmgawa kenhpan 150,920 4/1953 Australia...................... 254/122 Feb. 21, 1968 Primary Examiner-Harvey C. Hornsby Ja an Assistant Examiner-Merle F. Mafiei 43/ 12829 Anorney-McQ lew and Toren ABSTRACT: In a small-sized hoist device, an inner annular 10Clllms,6 Drawing Figs. member disposed in spaced relationship to an outer annular 1 member is employed in transmitting the input force to the drive shaft. The inner annular member is mounted and rotates ht cl U04 with the shaft while the input force is delivered to the outer annular member which conveys the force through interlocking 254/167 f means to the inner member. The Interlocking means com- 186 188/134 72 1 prises a cage member holding a plurality of balls which fit into continuous threads formed in the oppositely arranged facing References Cited surfaces of the inner and outer annular members. UNITED STATES PATENTS 1,584,140 5/1926 Powell.......................... 188/829 United States Patent [72] Inventors Hideolwama [22] Filed [73] Assignee [32] Priority [54] SMALL-SIZED HOIST DEVICE I A 74 4 H PATENTED nu: 7:971

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THKESHI SHITH SMALL-SIZED I-IOIST DEVICE SUMMARY OF THE INVENTION The present invention is directed to a hoist device which can also be utilized as a traction apparatus, and more particularly, it is directed to an arrangement for delivering input power to a main or driven shaft which permits the input device to be interlocked with the shaft.

Small-sized or portable hoists are known which utilize a chain wheel for lifting and lowering loads and also as a traction apparatus for pulling or dragging heavy members. In such hoists a main shaft is interlocked with the chain wheel and the input force is delivered to the shaft by a working lever or other hand chain wheel.

In these known devices, a friction plate and ratchet wheel have been interposed axially along the main shaft between a male screw member and a female screw member. The male member is mounted on the main shaft by a spline fit. A working lever or a hand chain wheel is secured to the female screw member and. with the inter-engagement of the threaded portions of the male and female screw members, the main shaft is integrally engaged with the driving side of the device and transmits power to the chain wheel for lifting a load. However, when the load is to be lowered, the female member secured to the male member must be loosened by providing an input power acting in the opposite direction by means of a changeover ratchet. Unfortunately, once the female sleeve is threaded into tight engagement, it is difficult to loosen it because of the strong frictional forces developed. Consequently, in such an arrangement the efficiency of the operation is considerably reduced, but, further, due to the character of the threaded members, a brake device cannot be made into a sufficiently small size and as a result, the traction apparatus cannot be reduced in size.

Accordingly, the primary object of the present invention, is to provide an interlocking engagement between an inner sleeve and an outer sleeve disposed about a drive shaft for imparting rotation to the shaft and thereby overcoming the disadvantages previously encountered in reversing the direction of operation of the hoist.

Another object of the invention is to provide an interlocking arrangement which is easy to assemble and does not require special attention when the hoist is being repaired or maintained.

Yet another object of the invention is to provide an interlocking arrangement which utilizes a cage member and ball members disposed between similarly shaped continuous threads in the oppositely disposed surfaces of the inner and outer sleeves about the drive shaft.

A still further object of the present invention is to provide a hoist construction which is simple in arrangement, easy to maintain and repair, and efficient to operate.

Therefore, in accordance with the present invention, a main or drive shaft for a small-sized hoist is arranged to be selectively engaged with an interlocking gear means for driving a chain wheel which in turn effects lifting, lowering and pulling operations. Mounted on the shaft by a spline fit is an inner sleeve which is axially slidable along the shaft but which rotates the shaft about its axis. An outer sleeve surrounds the inner sleeve in radially spaced relation and is in operative engagement through a ratchet wheel with a working lever for providing the input force for the hoist device. The oppositely arranged facing surfaces of the inner sleeve and outer sleeve each have a similarly shaped continuous thread formed therein. Positioned in the annular space between the sleeves is a cage member and a plurality of ball members which extend between the ppositely formed threads for locking the sleeves together and transmitting the driving force to the main shaft.

The end of each sleeve adjacent the chain wheel has an outwardly directed flange in spaced relationship from the other flange and arranged to receive a braking device therebetween. A changeover ratchet or pawl means is provided in the working lever and acts against a ratchet formed in the outer surface of the outer sleeve for reversing the direction of operation of the hoist device.

The ball members providing the interlocking action between the sleeves are held in position in slots which extend transversely to the direction of the threads in the sleeves. The width of the slots is smaller than the diameter of the balls so that the balls are held between the cage member and the threaded inner surface of the outer sleeve. Due to this arrangement of the cage member and the interlocking balls, the inner and outer sleeves can be easily released from engagement and the lifting operation of the hoist reversed.

. The various features of novelty which characterize the invention are pointed out withparticularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. IA is a view partly in section through a small-size hoist device, embodying the present invention, in the engaged position for performing work;

FIG. 1B is a partial sectional view, similar to FIG. IA, but with the hoisting device in the disengaged position;

FIG. 2 is a detail view, partly in section, of the hoist device illustrated in FIG. 1;

FIG. 3 is a detail view, partly in section, of the interlocking means employed in the present invention;

FIG. 4 is a detail end view of a portion of the device shown in FIG. 3; and

FIG. 5 is an enlarged transverse view partly in section, of a portion of the device shown in FIG. 1A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, a small-sized hoist device A has a housing B enclosing a load chain wheel or sprocket l with a chain and hook 1a passing over the wheel. Affixed to the upper part of the housing is a hook lb for mounting the hoist device on a support. Extending through the housing B, transversely to the direction of the chain la, is a main or drive shaft 3 which has a gear member 3a at one end selectively engageable with a dual gear 2 for driving the chain wheel 1. The shaft 3 extends through but is not in engagement with the chain wheel 1. In FIG. 1A the shaft 3 is shown in engagement, under a spring bias, with the dual gear 2 for driving the chain wheel, while in FIG. 1B the shaft is disengaged from the gear 2 with the chain wheel in the idle position.

On the opposite end of the shaft 3 from gear 30, an inner sleeve 4 is engaged on the shaft by a spline fit which permits the sleeve to be axially slidable on the shaft, but to rotate with the shaft. The outer surface of the inner sleeve 4 has a special continuous male thread 4" extending along a part of its surface. The thread is formed by an arc-shaped groove 4" cut into the outer surface of the inner sleeve with a flatland 4' extending between the grooves 4". An outer sleeve 7 laterally encloses the inner sleeve 4 and is spaced from it in the area of its continuous thread 4" forming an annular space 5a therebetween. The inner surface of the outer sleeve 7 has a continuous female thread disposed opposite the thread in the inner sleeve and is formed at the same pitch. Accordingly, the female thread 7" has an arc-shaped groove 7' cut into the inner surface of the outer sleeve 7 and the sections of the thread are spaced apart by flatlands 7".

Spaced between the inner and outer sleeves 4 and 7, is a cage member 6 which positions a group of balls 5 within the annular space 5a, with the individual balls being fitted into engagement into the oppositely disposed threads 4, 7" of the inner and outer sleeves, respectively. As can be noted in FIG.

S, the cage member 6 is spaced slightly closer to the inner sleeve than to the outer sleeve and it is provided with a number of slots 6" extending in a direction transverse to the direction of the threads 4", 7" on the opposite sides of the annular space 5a. As can be noted in FIG. 3, the cage member 6 with its slots 6" position the balls 5 for locking interengagement within the threads in the inner and outer sleeves. The width of the slots 6" is slightly less than the diameter of the balls 5, and, as a result, the cage member cooperates with the outer sleeve to form a device for holding the balls in place.

At its end adjacent the chain wheel 1, the cage member 6 has a number of outwardly directed flangelike projections 6 which are secured to the inner surface of the outer sleeve. Just outwardly from the flanged end of the cage member 6 is an annular member 8 which acts as a retainer ring to prevent the displacement of the balls 5 from within the annular space 5a. The interaction of the balls within the male and female threads in the inner and outer sleeves, respectively, provide an interlocking action between the sleeves for transmitting the input force from the outer sleeve through the inner sleeve to the shaft 3.

At its end adjacent the chain wheel the inner sleeve 4 has an outwardly directed flange 4a and the adjacent end of the outer sleeve has a similarly arranged flange 7a spaced from the flange 4a. A braking ratchet wheel 13, having brake plates 12 on its opposite surfaces, is disposed between flanges 4a and 7a and is cooperable with conventional braking pawl means. A ratchet 11 is formed on the outer surface of outer sleeve 7, and is operatively engaged by a changeover ratchet or pawl means mounted in a working lever 9 which supplies the working force to the hoist device.

When lever 9 is oscillated, ratchet or pawl means 10 steps ratchet 11 and outer sleeve 7. This causes outer sleeve 7 to be threaded along inner sleeve 4 by virtue of the balls 5 engaged in the respective helical grooves in the facing surfaces of sleeves 4 and 7. As sleeve 7 thus moves inwardly, braking ratchet 13 with its brake plates 12 is clamped firmly between flanges 7a and 4a, flange 40 being provided on inner sleeve 4. As a result, the inner and outer sleeves are interconnected to be angularly advanced as a unit, so that sleeve 4 rotates shaft 3 and pinion 3a to rotate dual gear 12 and thus chain sprocket 1. Upon actuation of ratchet pawl means 10 for changing over, sleeve 7 is threaded to the right relative to sleeve 4 releasing the clamping of ratchet l3 and brake plates 112 by flanges 4a and 7a for loosening the chain hoist. ln the tightening of sleeves 4 and 7 on each other, balls 5 move within transverse slots 6" in effecting the interlocking engagement of sleeves 4 and 7 with the interposed ratchet 13.

When shaft 3 is pulled to the right, pinion or gear 30 is disengaged from dual gear 2 and, if the braking pawl is then released, the chain hoist may unwind" under its own weight, or may be unwound or moved in the unwinding direction. Thus, the hoist operator optionally can connect the hoist driving means to the sprocket l or disconnect the hoist driving means from the sprocket I for idling movement of sprocket l and the chain In trained therearound. It will be noted that pinion 3a and shaft 3 are normally biased to the left, to engage pinion 3a with dual gear 2, and that a positive manual force must be exerted on the handle, at the right in FIGS. 1A and 1B, to disengage pinion 3a from dual gear 2.

As described above, the arrangement of the cage member 6 retains the balls between it and the outer sleeve 7, accordingly, if the inner sleeve 4 is removed from the device, the cage member retains the balls in position. In view of this arrangement overhauling, assembly, and inspection of the hoist device can be easily carried out without any displacement or loss of the balls.

With the interposition of the balls 5, held in place by the cage member 6 within the annular space 5a between the inner and outer sleeves 4, 7, the device can be tightened for lifting operations or loosened as required in an easy and smooth manner. As compared to the direct engagement of a conventional male and female thread there is not only the advantage of ease in assembling and overhauling, but also the friction losses between the inner and outer sleeve are relatively small and, accordingly, a brake device having the requisite brake force which is small in size and operates smoothly is afforded.

What is claimed is:

1. A small-sized hoist device, also employable as a traction apparatus, comprising, in combination, a shaft; a hoist device for lifting, lowering and moving loads; optionally disengageable means interconnecting said shaft and hoist device; a first sleeve axially slidably mounted on said shaft and engaged with said shaft for rotation about its axis; a second sleeve embracing said first sleeve with radial clearance to form an annular space therebetween; a first helical thread-forming groove on the outer surface of said first sleeve; a second helical thread forming groove on the inner surface of said second sleeve; said grooves having the same pitch; balls disposed at said annular space in said grooves; whereby said first and second sleeves are threadedly interconnected through said balls; hoistoperating means connected to said second sleeve to rotate the same; and coupling means operable, responsive to threading of said second sleeve along said first sleeve by operation of said operating means, to couple said sleeves for conjoint rotation with said shaft; and an annular cage positioned within said annular space and spaced from said first and second sleeves, said cage retaining said balls in predetermined spaced relation.

2. A small-sized hoist device, as set forth in claim 1, wherein outwardly directed flangelike projections are formed on one end of said cage and extending outwardly into engagement with said second sleeve, and an annular member affixed to said second sleeve adjacent the flange end of said cage and arranged to prevent the displacement of said balls from between said cage and said second sleeve.

3. A small-sized hoist device, as set forth in claim 2, wherein said cage member has a plurality of separate spaced slots formed through its surface, said slots being disposed in substantially parallel relationship for receiving said balls, said slots extending transversely to the direction of said grooves in said first and second sleeves.

4. A small-sized hoist device, as set forth in claim 3, wherein said grooves in said inner and outer sleeves comprise a concave surface formed in the surface of said sleeves to afford at least a plurality of punctiform contact locations between said balls and said sleeves.

5. A small-sized hoist device, as set forth in claim 3, wherein said grooves in said first and second sleeves comprise a continuous arc-shaped recess arranged to receive said balls, flatland surfaces being formed between the adjacent recesses of said grooves.

6. A small-sized hoist device, as set forth in claim 3, wherein said slots in said cage member have a width slightly less than the diameter of said balls and said cage being spaced slightly closer to said first sleeve than to said second sleeve whereby said balls are held by said cage within the groove in said outer sleeve and extend through the slots in said cage into engagement with the groove in said inner sleeve.

7. A small-sized hoist device, as set forth in claim 1, wherein said operating means comprises a ratchet wheel formed on the outer surface of said second sleeve, a changeover ratchet in engagement with said ratchet wheel, and a lever operatively engaged to said changeover ratchet for driving said ratchet wheel and in turn operating said hoist device through the interlocking engagement of said first and second sleeves.

8. A small-sized hoist device, as set forth in claim 7, wherein said first sleeve is secured to said shaft by a spline fit.

9. A small-sized hoist device, as set forth in claim 7, wherein said means for interconnecting said shaft and hoist device comprises a gearwheel positioned at one end of said shaft, gear means formed on said hoist device, and an interconnecting gear member arranged to optionally engage said gearwheel on said shaft'and being in meshed engagement'with said gear means on said hoist device.

10. A small-sized hoist device, as set forth in claim 1, wherein said coupling means comprises an outwardly directed flange at one end of said first sleeve and an outwardly directed flange at the corresponding end of said second sleeve, said flanges being in axially adjacent spaced relation; and a braking 5 element interposed between said flanges and gripped between said flanges responsive to threading of said second sleeve along said first sleeve by operation of said operating means.

* l IR t i 

1. A small-sized hoist device, also employable as a traction apparatus, comprising, in combination, a shaft; a hoist device for lifting, lowering and moving loads; optionally disengageable means interconnecting said shaft and hoist device; a first sleeve axially slidably mounted on said shaft and engaged with said shaft for rotation about its axis; a second sleeve embracing said first sleeve with radial clearance to form an annular space therebetween; a first helical thread-forming groove on the outer surface of said first sleeve; a second helical thread-forming groove on the inner surface of said second sleeve; said grooves having the same pitch; balls disposed at said annular space in said grooves; whereby said first and second sleeves are threadedly interconnected through said balls; hoist-operating means connected to said second sleeve to rotate the same; and coupling means operable, responsive to threading of said second sleeve along said first sleeve by operation of said operating means, to couple said sleeves for conjoint rotation with said shaft; and an annular cage positioned within said annular space and spaced from said first and second sleeves, said cage retaining said balls in predetermined spaced relation.
 2. A small-sized hoist device, as set forth in claim 1, wherein outwardly directed flangelike projections are formed on one end of said cage and extending outwardly into engagement with said second sleeve, and an annular member affixed to said second sleeve adjacent the flange end of said cage and arranged to prevent the displacement of said balls from between said cage and said second sleeve.
 3. A small-sized hoist device, as set forth in claim 2, wherein said cage member has a plurality of separate spaced slots formed through its surface, said slots being disposed in substantially paralleL relationship for receiving said balls, said slots extending transversely to the direction of said grooves in said first and second sleeves.
 4. A small-sized hoist device, as set forth in claim 3, wherein said grooves in said inner and outer sleeves comprise a concave surface formed in the surface of said sleeves to afford at least a plurality of punctiform contact locations between said balls and said sleeves.
 5. A small-sized hoist device, as set forth in claim 3, wherein said grooves in said first and second sleeves comprise a continuous arc-shaped recess arranged to receive said balls, flatland surfaces being formed between the adjacent recesses of said grooves.
 6. A small-sized hoist device, as set forth in claim 3, wherein said slots in said cage member have a width slightly less than the diameter of said balls and said cage being spaced slightly closer to said first sleeve than to said second sleeve whereby said balls are held by said cage within the groove in said outer sleeve and extend through the slots in said cage into engagement with the groove in said inner sleeve.
 7. A small-sized hoist device, as set forth in claim 1, wherein said operating means comprises a ratchet wheel formed on the outer surface of said second sleeve, a changeover ratchet in engagement with said ratchet wheel, and a lever operatively engaged to said changeover ratchet for driving said ratchet wheel and in turn operating said hoist device through the interlocking engagement of said first and second sleeves.
 8. A small-sized hoist device, as set forth in claim 7, wherein said first sleeve is secured to said shaft by a spline fit.
 9. A small-sized hoist device, as set forth in claim 7, wherein said means for interconnecting said shaft and hoist device comprises a gearwheel positioned at one end of said shaft, gear means formed on said hoist device, and an interconnecting gear member arranged to optionally engage said gearwheel on said shaft and being in meshed engagement with said gear means on said hoist device.
 10. A small-sized hoist device, as set forth in claim 1, wherein said coupling means comprises an outwardly directed flange at one end of said first sleeve and an outwardly directed flange at the corresponding end of said second sleeve, said flanges being in axially adjacent spaced relation; and a braking element interposed between said flanges and gripped between said flanges responsive to threading of said second sleeve along said first sleeve by operation of said operating means. 